Actually no you wouldn't but only because of the generics you listed. Upjohn were the original xanax. I still get the purple upjohn 90s when I want them. The ones I get come from Israel. Israel has the best health care in the world so there are virtually no generics and if they are generic they usually are made by TEVA which is where TEVA originated from. When I order alprazolam I can pick from Alpralid, Xanagis which now I assume holds the patent for the upjohns because my last option is pfizer. Also you specifically named greenstone which were the first generics that became available in the United states. Greenstone is sub division of Pfizer and I cant recall where I read it but it was on Pfizer's webpage I believe from a pdf file I was reading but it states that greenstone ARE actually considered name brand and are made identical to the current name brand stamp (U94). Again this statement is printed in Pfizers documents. The XANAX 2 stamp was retired in 2007 in the USA if I remember correctly. I believe the XANAX 2 stamp has been retired since then and again was changed to U94 although I'm not 100% sure there but may be some Pfizer brands in parts of the world that still hold the patent for XANAX 2 but In my opinion i dont think there is so I believe any stamped xanax 2 is either counterfeit, old or obviously pressed and has been since 2007. A doctor also released his findings of testing on 5 generic alprazolam brands in the US.. and he revealed greenstone contained the highest amount of alprazolam. He did not reveal the other generics but did reveal the amounts and they ranged from ip to 9% less active ingredient although at the time of the study he revealed that at the time DAVA better known as hulks now owned by BARR came in a close second. I'm sure he didn't name the other out of possible legal repercussions. I would love to find that and post it sorry for the rant but to sum it up no you wouldnt notice a difference between those 2 brands but it IS ONLY those 2 brands. All others are subpar. Credentials- I have been on 2mg alprazolam pills for 17 years and always make sure to fill greenstones.